Research On Preparation And Sintering Process Of Aqueous3Y-ZrO₂Paste

3Y-ZrO2ceramics has been application prospect of dental porcelain materials, because it has higher breaking strength, higher fracture toughness and lower brittleness, what is more, the aesthetic effect which can match better with the tooth color of human beings. However some characteristic of3Y-ZrO2ceramics restrict its self-development, such as higher strength, higher hardness and its difficult to machining. The Solid Freeform Fabrication has used water as the substrate, the powder of3Y-ZrO2was configured to ceramics paste which was used to molding, and it solved better the problem of molding of3Y-ZrO2ceramics. The chiefly precondition which broaden its application in the fields of dentistry is configured slurry which has characteristics of stable property, uniform composition, excellent dispersion and extruding performance. Another chiefly premise is configured3Y-ZrO2ceramic body which has outstanding sintering performance. Therefore, the key of the paper is research on preparation and sintering process of3Y-ZrO2paste. The paper will acquire the excellent formula via analyzing influence of the slurry property which is affected by solids loading, dispersant content and pH. And it analyzes the effect of extruding force and liquid content which caused by different extrusion process parameters in the extruding process of the3Y-ZrO2paste. And it analyzes the effect of3Y-ZrO2ceramic body performance which is caused by sintering parameters.Firstly, the paper analyzes slurry property which is affected by solids loading, dispersant content and pH. And the slurry performance is valued by viscosity which is testing in the test. The study shows that the viscosity of slurry adds with the ball milling time increase, soon after a certain value, the final determination is8hours. The viscosity of slurry shows increasing trend along with solids loading increase, when solids loading reaches42%, the slurry performance is best and stable. The study shows that the viscosity of slurry increase with the decrease of after the first with dispersant content increase, when dispersant content reaches3.5%, it precisely ad forming hydration shell with other annexing agent which wraps the surface of solid particles. The viscosity of slurry shows decrease, soon after a certain value with PH increase, and we acquire the aqueous paste which suit molding by adding0.5ml10%HCl liquor in30ml slurry.Secondly, in order to verify the aqueous paste whether if suits molding, the paper researches on extrusion process of3Y-ZrO2ceramic paste. The extruding force of the stabilizing phase and the liquid content of the extrudeate which is affected by plunger velocity, extrusion die length and diameter. And it analyzes the rule of the paste in the continuous extrusion. The study shows that the extrusion force increases basically in linear, along with the increase of plunger velocity and extrusion die length, as well as the decrease of extrusion die diameter. The liquid phase deviation vector of the extrudate decreases with the increase of plunger velocity. When plunger velocity is higher than0.08mm/s, the liquid migration basically does not occur at all. And the liquid content of extrudate basically invariant compares with the original paste. The liquid phase deviation vector of the extrudate increases with the increase of extrusion die length and decrease of extrusion die diameter. When the extrusion die diameter chooses lmm and the extrusion die length is shorter than12mm, the liquid content of extrudate basically invariant compares with the original paste.Finally, the green body of3Y-ZrO2ceramics which is extrusion molded sinters at atmospheric pressure in different sintering temperature and holding time. And the paper analyzes the property of the green body which is affected by sintering temperature and holding time. The shrinkage, the volume density and relative density of the body increases soon after a certain value, when the rising of sintering temperature and holding time. And keep the body warm in150min at1490℃. The breadth shrinking of the body is23.0096%. The thickness shrinking of the body is22.938%. The volume density of the body is5.8544g/cm3. The relative density of the body is96.7669%. The bending strength of the body increases and decreases of after the first, when the rising of sintering temperature and holding time gradually. When keeping the body warm in150min at1490℃, the bending strength of the body is largest which can research27.57MPa. The porosity factor of the body decreases gradually with the rising of sintering temperature and holding time.